Optical block



FIG. 1 is a perspective view of an optical block.

FIG. 2 is a left side elevational view of the optical block.

FIG. 3 is a right side elevational view of the optical block.

FIG. 4 is a top plan view of the optical block; and,

FIG. 5 is a front end elevational view of the optical block, the opposite end being a mirror image thereof.

The bottom of the optical block forms no part of the claimed design. 

CLAIM The ornamental design for an optical block, as shown and described. 